While national governments have struggled to work together to solve the global-climate crisis, mayors are cooperating through organizations like the C40 Cities Climate Leadership Group (C40) to deliver concrete results.

How do Australians do so many things so well? They combine tremendous pride in their work with a friendly, light-hearted sense of humor that you can't help enjoying. Of the 32 countries we have visited as a family, Australia is our new #1.

Let's get this one out of the way. San Diego is the textbook example of beautiful year-round climate. It's never too hot and never too cold, with a very minimal amount of that pesky California fog to get in the way--when it does roll in, it burns off pretty quickly in the morning.

Focusing on where our humanity intersects with data is the future of work. Bringing the human element back into work will inevitably pay off in the bottom line as well. Reclaiming that is what all companies and individuals need to focus on in our world today.

A bull shark emptied Australia's Bondi Beach of people for nearly two hours on Friday, and had its 15 minutes of fame. But by Saturday, it had all but been forgotten in favor of a different breed of shark.

Moral and intellectual clarity about the world we live in are not compatible with self-exculpating glibness. Our adversaries' wrongness does not mean we are in the right. The substance of the terrorists' victory lies exactly in their success in having persuaded Western societies to empower our own authoritarian regimes.

Today, more than ever, I am extremely proud to be Australian. At a time of deep crisis, the people of Sydney have shown me that equality, tolerance and non-violence are not just hipster rhetoric. We stand together as people supporting other people in the most human of ways, and we say #IllRideWithYou.

While untrained domestic lone wolves have been inspired to undertake violent attacks, unlike their more sophisticated foreign counterparts, they often die or are captured shortly after initiating violent confrontations, with more limited casualties. Still, even untrained loners can kill dozens if a nexus of factors align.